Yes to both questions. Overall, getting kids to start thinking
seriously seems to help them become smarter, more adaptable adults
(there have been some experiments with teaching young children
philosophy and getting them discuss it, and it has apparently had
positive results). And if you can think critically at an earlier age,
fewer bad memes will be integrated in your basic worldview.

I have discussed with some fellow transhumanist the possibility of
writing transhumanist and philosophical children's stories. Everything
from the adventures of the girl epistemia to Spot gets uploaded. But
the most important influence is of course adults around the children -
try to promote critical thinking (and *thinking* in general) whenever
you are around them. The results are quite rewarding.